Did you try Forest Park, a couple of miles outside Cha Am on the road to Hua Hin? It's full practically every evening , very popular with Thais and the food is excellent, especially the seafood and fish..... only downside is that the waiters speak practically no English and are a bit wary of acknowledging your existence in case they (or you) lose face, so you could find yourself waiting for some time before someone plucks up courage to come and take your order.

As a general rule of thumb,

-If a restaurant is packed with Thai people, this is nearly always a reliable indication that the food is very good and reasonably priced (if not dirt cheap).

-If a restaurant is packed with foreigners, that's another matter.... it could be the restaurant is mentioned in guide books, could be that tourists see other foreigners eating there. It doesn't necessarily mean that the food will be particularly good or particularly good value. The only time I've ever had food poisoning in Thailand was after eating in the Falang Bar in Chumphon. As the name suggests it caters mainly for falangs and it was by no means deserted, quite busy in fact.

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